The Iraq Defense Ministry on Thursday confirmed that a top aid to Abu Bakr al-Baghdadi, the leader of the Islamic State of Iraq and the Levant (ISIS), has died. According to an Al Arabiya report, the aide is believed to have died during a U.S. airstrike on Mosul. Two other top ISIS officials were also killed in the attack, including a Tel Afar military official.

Early reports on the airstrike in Turkish and Kurdish media had claimed that Bagdadi himself had been killed in the airstrike. Those reports have been denied by the U.S. military, though no official statement on the attack has been made by the U.S. A U.S. military spokesperson quoted in an NBC News report stated that the aide and other officials had not been specifically targeted by the attack.

ISIS began a widespread military campaign in parts of northern Iraq in June. The organization has claimed much of Iraq as part of its caliphate and also controls a significant portion of the northern part of the country.

Though President Obama has made it clear that U.S. troop deployments to Iraq will remain minimal, the U.S. has been leading an air campaign over ISIS territory since early August. U.S. Secretary of State John Kerry stated in June that U.S. support of the Iraqi government will remain

As the bombing campaign has progressed, ISIS has turned to more violent tactics in an effort to shore up support. The organization beheaded U.S. journalist James Foley in mid-August and just this week also beheaded American-Israeli journalist Steven Sotloff. Both men were kidnapped by Syrian forces in late 2013.

With ISIS serving as an example of regional spillover from the Syrian civil war, President Obama has called on NATO leaders to join the fight against the organization. The NATO summit in Wales this week was supposed to focus on Russia’s invasion of Ukraine, but a New York Times report suggests that the U.S. and U.K. are working primarily to gather a coalition to oppose ISIS.